Tyson used the time to publicly explain to rapper B.o.B. that the Earth is round, not flat as the rapper recently asserted in an extensive rant on Twitter and in a diss track titled “Flatline” aimed at Tyson. During Tyson’s insult-laden rebuttal, he also pointed out the danger to society when high-profile people like rappers with millions of Twitter followers and political candidates willfully ignore basic science.

Tyson concluded his explanation by proving the law of gravity and dropping the mic.